I cannot sent mail by using Postfix (SMTP) on Ubuntu Server 11.04. So, there must be some errors, But where to see the error message?
Have you already stumbled upon this comprehensive Postfix Debugging Howto? There's the following notice concerning logging:
Postfix logs all failed and successful deliveries to a logfile. The file is usually called
/var/log/mail; the exact pathname is defined in the
syslog.conf specifies where the
I was not able to locate logs anywhere and I was running Ubuntu 20.04 LTS, turns out this was a permission issue for some strange reason. the problem was with the syslog permission. The following helped me to resolve it:
sudo chown syslog:adm /var/log sudo chmod 0775 /var/log sudo service rsyslog restart sudo service postfix restart